That was then. When I first met Katy last year, she was five months pregnant, dressed like a county lineman and knee-deep in mud. She was one of a crew slogging through a windy marsh at Point Reyes National Seashore on the way to a patch of alien cordgrass, to check if their effort to smother it a year ago had been successful. Katy today is a self-employed field biologist, an alien plant eradication specialist. She works for the San Francisco Estuary Invasive Spartina Project to help rid San Francisco Bay and the nearby coast of several species of Spartina, a robust cordgrass that is rapidly invading saltmarsh habitat and threatening the native cordgrass, Spartina foliosa.

When I met Katy again last summer, it was in a brown-shingle home in Stinson Beach, Marin County, that she shares with her husband, a veterinarian. With one arm around four-month-old Zofie, she struggled to say why biology had won out over her other ambitions.

“There’s always been two sides to me,” she said, looking out toward the slope of Mount Tamalpais. “I like to have access to San Francisco and all the culture. But I chose to live here, just over the hill.”

Maybe it was the thrill of childhood field trips, or the breathtaking views on an Alaskan holiday, but the clincher may have been the Marine Mammal Center bumper sticker she happened to see while she was staying with her mother in Berkeley after her graduation from college in 1986. She remembered visiting the center in Marin County when she was a child and, on impulse, signed up as a volunteer. Within a few months, she had a full-time job in the education department. She stayed on for ten years.

While running a program with Oakland’s Castlemont High School students, she became intrigued by the problem of invasive plants. “We went out to sites such as the Martin Luther King, Jr., Shoreline, where we studied the marsh, including Spartina alterniflora,” she said. This tough Atlantic cordgrass was spreading rapidly, outcompeting native cordgrass, turning mudflats to saltmarshes, threatening the habitat of native plants and animals, and slowing creek water flow. It had been planted along the Bay in the 1970s by the U.S. Army Corps of Engineers in a well intentioned but ill-fated attempt to restore local marshlands.

“We discussed how we, as individuals, could help prevent some of the human impacts on the ocean, coast, and the Bay,” Katy continued. “I decided I wanted to learn more about invasive species, and to work with an expert. So I sought out Don Strong,” professor in the Department of Evolution and Ecology at the University of California, Davis, who was researching S. alternifolia. Strong hired her to help him at the Bodega Marine Laboratory, and encouraged her to pursue a graduate degree.

In 1998, at age 30, Katy earned her master’s degree in biology at San Francisco State University. She worked with the East Bay Regional Park District examining the Spartina invasion at Cogswell Marsh, and the district used the results of her studies to help make management decisions for that site. This led to her joining the multi-agency Invasive Spartina Project, led by the Coastal Conservancy. Alien Spartina has spread at a relentless rate on the Bay and now covers an estimated 2,000 acres. “It’s becoming the monster in the closet,” Katy says.

She puts in eight-hour days trekking, boating, and kayaking, collecting grass samples, snapping photographs, taking GPS readings, compiling data, and explaining the Spartina threat to park officials, businesses, and curious passersby. Yet so far, despite the use of herbicides, spades, and tarpaulins, she says that the battle has just begun. Smothering the plants has been slow work, and there is only a small window, a few weeks each autumn, when spraying with herbicides is possible, because Bay marshes are home to the endangered California clapper rail, which breeds in cordgrass. Yet Katy remains hopeful. She believes in the work, saying there’s “nothing I don’t like” about it. I delicately note that biologists are hardly paid a princely sum. True, she says. “We can’t really afford to buy a home in this area. But, then, . . .”

She stops and looks around. Outside the porch door, Mount Tamalpais rises golden against a blue sky. Across the road, Bolinas Lagoon is still. I pause and take in the quiet, then shake hands and leave. No doubt about it, this is one fox that’s found its lair.

SHIRLEY SKEEL, an independent radio and print journalist based in Berkeley, is a regular contributor to Coast & Ocean.